There is an increasing demand from users to have control over electrical equipment and for that control to be exercised remotely, rather than just from a fixed switch or dimmer control, such as a wall switch/dimmer. This remote control requirement is particularly applicable to the control of lighting units or luminaires in and around the home and in and around the work place. In the case of luminaires, these remote control requirements can include, by way of example only, an on/off function including a timed or motion sensor controlled on/off function, a dimming function, changing the colour temperature of the light or changing the colour of the light emitted and touch sensor control. This list of examples is not intended to be exhaustive but rather serves to illustrate the wide range of functionalities than might be controlled by remote operation. Further examples are listed later in the description.
In addition to the requirement to control light fittings/luminaires remotely, luminaires are becoming more intelligent in that they are now capable of collecting data both about the environment around the luminaire and about the performance of an individual light engine/luminaire itself. Furthermore, this intelligence and information gathering capability is increasing rapidly with each new generation of luminaires. There is therefore a need to relay various types of data from a light fitting/luminaire back to a data repository for the purpose of analytics, reporting and reactive functions.
Many of the bulbs, lamps and luminaires now on sale include LED light sources. As LEDs enter mainstream lighting applications consumers expect their operation to mimic traditional lighting units such as incandescent bulbs and fluorescent tubes. Dimming of LEDs presents a challenge because of the unique power demands of LED chips. An LED emits light when the forward voltage is greater than a threshold governed by the semiconductor material used in the LED.
A number of systems already exist for dimming LED light sources. In addition to dimming by means of an Integrated Circuit in the light engine, analogue dimming of an LED is possible. This involves reducing the forward voltage applied to the LED, leads to a noticeable change in the colour of the light. By contrast, digital dimming generally produces almost no change in the colour of the emitted light. One method of digital dimming relies on keeping the forward voltage constant and rapidly cycling the LED on and off. Altering the duty cycle, which is the ratio of the pulse duration to the signal period, changes the brightness of the light emitted. Digital dimming can be achieved by combining an LED driver with a suitable logic chip generating the duty cycle, or it can be achieved in integrated circuits having both functions in one package.
A number of systems already exist by which remote control can be achieved. For example technical standards for Digital Addressable Lighting Interface (DALI)® have been developed for network-based systems that control lighting in building automation. Typically a DALI® network consists of a controller and one or more lighting devices (e.g. electrical ballasts and dimmers) each of which have a built in DALI® interface. The controller can monitor and control each light by means of a bi-directional data exchange. Data is transferred between the controller and the devices by means of an asynchronous, half-duplex serial protocol over a two-wire data bus. It will be appreciated that this requires specialist cabling and special DALI® compatible control components within or associated with each luminaire to be controlled. This is both expensive to install, requires a skilled electrician and/or controls engineer to perform the installation, and is very difficult to retro-fit into an existing lighting installation where no such control system was ever envisaged.
In a further example, digital dimming technology can be installed in a home or in an office using an RE (radio) control system such as those supplied by Rako Controls Limited of Knight Road, Rochester, Kent, ME2 2AH. However, planning a lighting project including this type of dimming technology can be confusing, especially with the vast array of lamp types and fittings now available. Typically a special wall-mounted control panel is required and a radio controlled dimmer unit, which is physically quite large in size, has to be wired in series with each luminaire, or group of luminaires to be controlled. This is both an expensive solution and inevitably requires a skilled electrician and/or controls engineer to perform the installation.
A further example of a known control system is the EYENUT® system supplied by Harvard Engineering PLC of Tyler Close, Normanton, Wakefield, West Yorkshire, WF6 1RL which uses the ZigBee protocol and components. This type of system requires an EYENUT enabled driver and/or dimmer to be connected to every luminaire in the system. These are controlled by one or more EYENUT Gateway devices, with each Gateway device being connected by Ethernet cabling to an EYENUT hub which in turn is connected to a web interface.
As with the other systems described above, a skilled electrician and/or controls engineer is required to perform any installation. Plus there are considerable costs involved.
These are just three examples of known wireless protocols that have application in the lighting field and further protocols are described below.
By way of further prior art, WO2013142292 discloses the application of a Digital Control Ready (DCR) lighting fixture disposed in one location and coupled to a Digital Light Agent (DLA) disposed in a second location to control the light output of the DCR light fitting. A DCR-enabled lighting fixture therefore responds to digital control signals from a separate digital light agent (DLA) instead of analogue dimming signals.
None of the arrangements described above can be easily adapted to retrofitting to an existing lighting installation, including adapting an existing installation so that it can be controlled by smart home systems utilising for example, the ZigBee® Alliance wireless protocols. Nor do these arrangements allow for the reporting and relaying of data to and from a light fitting/luminaire in a two-way communication process.
It is the object of the present invention to overcome or at least mitigate some of the problems with the prior art outlined above, and to provide a cost effective 2-way communication module that also provides a remote control function, and that is easy to install both in new installations and as a retrofit, without any need for additional wiring or rewiring, and preferably without the installation process requiring any tools or the services of a skilled electrician/controls engineer.